<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
<style type="text/css">
body{margin:0;}
.box{width:1000px; height:800px; background:url(img/yema_img.jpg) no-repeat;
background-size:100%; -webkit-mask:url(img/mask.png) no-repeat; transition:0.05s;}
</style>

</head>
<body>
<div class="box">

</div>
<script>
var oDiv = document.getElementsByTagName("div")[0];
	oDiv.onmousemove = function(ev){
		var oEv = ev ||event;
		oDiv.style['-webkit-mask-position'] =(oEv.clientX-200)+"px "+(oEv.clientY-200)+"px";
	}
</script>
</body>
</html>
